Donal.

Your reasoning is FLAWED. You are using two different sails, which
cancel out your statement.

However, there is a easier proof that holds true. Use a performance
curve and you will see that your statement may be correct, with the
exception off the wind "Bernoulli" is much more logical.
Off the wind we are getting greater lift from a looser, baggier sail and
the tell-tales streaming back as indicating Bernoulli's description of
flow and recovery area. I know you have seen this while reaching. That
is if you are using leech tell-tales. If not, why not?

Newton's 1st & 3rd laws say the tell-tales shouldn't be streaming to
windward and if Pim Example of the blown paper is correct, the Coanda
Effect should be curling the tell-tales back around the to the windward
side of the sail

Again, If I'm wrong and my eyes are deceiving me, please explain and
give an example.

Ole Thom